Long-Term Follow-Up of Patients with Vestibular Schwannomas after Initial Conservative Treatment

Background: The natural course of vestibular schwannomas is still not ascertained. The treatment options are surgery, radiosurgery or “wait-and-scan.” Conversion from observational to active treatment is reported in 15 to 85% of cases. The present study evaluates a long-term follow-up of initially conservatively treated patients, to identify a cut-off time for further follow-up. Methods: In the 10-year period (1997-2006), 161 consecutive patients (mean age 54 years, 53% males) were referred to our department with newly diagnosed vestibular schwannomas. The mean tumor size at presentation was 22 mm (6-60 mm), the tumor was intracanalicular in 27 cases (17%). Primary treatment was surgery in 62 (39%) and radiosurgery in 7 patients (4%), respectively. The remaining 92 patients (57%) were initially followed conservatively with regular MRI scanning. Results: Two patients from conservatively treated group were lost to follow-up, leaving 90 patients for further analysis. The mean tumor size in this group was 16 mm (6-40 mm). Overall 49 of these patients (54%) have received treatment (surgery in 23 and radiosurgery in 26 cases, respectively) after a mean of 25 months (10-67 months) of initial follow-up; 17 of these patients (35%) within 1 year from diagnosis. The remaining 41 untreated patients have been followed for a mean of 90 months (29-180 months), in 28 cases for more than 67 months. Conclusions: The results indicate that life-long follow-up is unnecessary in case of no evidence of tumor growth over several years. We propose termination of routine follow-up after 10 years.